Board drop hammer



Oct. 12 1926.

c. TALCOTT BOARD DROP HAMMER Filed April 1, 1925 2Sheets-Sheet 1 mvsN-loR ATTOR Y Tr, v

0a. 12 ,1926. 1,603,166 I M. C. 'TALCOTT BOARD DROP HAMMER Filed April 1.' 1925 2 Sheets-Sheet 2 INVENTOR Patented Oct. 1 926.

, UNIT E s re i S Monsoonc.- rALcoTT, or HARTFORD, connn'emicur, AssIGn'oR To THE. names a" SPENCER coM rnnxor HARTFORE'CONNEQTICUQ. A CORPORATION on colxrnnorr- Y BOARD nnor HAMM R;

Application filed April 1,,1925 SerialNo. 19, 841.

particularly, in the means of imparting the board-gripping pressure to the rolls of all thepairs. According to this invention the friction bar or member which constitutes the source of such ipre'ssure and which is controlled by the reciprocation of the ham mer, is connected with' the lifting rolls through anf v the pressure it exerts is imparted equally to equalizing lever, so that all therolls'. In the accompanying drawings, Fig. 1 1s a front elevation ofa board drop hammer I having the inven tion applied.

Fig. 2, a larger scale elevation of the head ,.st1"ucture thereof with the pressure links shown in section, the board clamp being omitted.

of Fi'g. 2, showing the board clamp.

* F ig. 4:, alarger detail of-the equalizing:

Fig. 6,-avertical section of amodified aIfrangement of the pressure link and equallz in lever. c. e Fig. 7, a: front elevation of Fig. 6; and, Fig. Sfurther modification of the e'qual izing mechanism. g 1

The hammer, as shown, comprises.a-mas-' sive base supporting a pair of; uprights 2, i which the h'ammer proper 3 is guided f .ture a' 1 d' the .other on the other. 3 As thus arranged both pinayl be directly belted, byopen belts, to; an adjacent power shaft not. .showinand thus be equally 'drivenso as tov v impart equal peripheral speed to 'thetwo The'spindle 8 drivesits' companion and a head structure Junitin'g theupper ends of the uprights land inwhich th e'llitting.

rolls and board clamp are mounted. The hammer is attached'to the board 4,]which isofgwood as usual, and is adapted to; be lifted by the lifting rolls" and to. be heldlifted when required by the board clamp is not a part of this invention; its general construction-and modeof operation, by the clamp rod 5 and foot treadlefi, will be apparent from the dra wingrand is as customdle ot each roll are journalled in 'movable carriers, whereby the roll may be moved rolls. roll marked 5.. The design of the board clamp arm12 of that roll toward and from'the board. By preference these carriersare' constitutedof sleeves 1-1; journalled to be rotated or rocked in the frame of the head structure and have the I roll spindles eccentrically journalled in them and they are also provided with radial arms 12 means of which they can be rockedv to produce the roll movement referred to.

The actuatingarms are extended from the eccentricsleeves at right angles to the d1rec each roll are rigidly joined by across bar tion of eccentricity and the two arms for;

fl3,so that bothsleeves of each roll are com-: pelled to rock in exact unison and thereby. impart exactly equal movement to both ends:

of the roll; for thispurpose the ends of the eccentric arms are formed as splithubs and; .thecross bars 13 are clampedin them. I g

The cross bars 13 of thetwo rolls, 8 and p I v I 10, o n the rear side of the head arezjoined' Fig. 3, a vertical section. on line IL-II in fixed relation by the link 14: and connected to an adjustment rod 15 which extends down ward through a lug 16' on the back side of one of the uprights 2 at which point the rod is threaded and provided with nuts on opposite sidesof the lugas indicated (see 'Figso that, by appropriate manipula tion of the nuts, the rod may be raised or lowered asrequired, thereby corresponding-1 ly shifting the position ot the rear rolls 8- I 7 it and 10 with reference to the board.

The rear rolls, 8 and 1O', .di 1 i en by large belt pulleys. fixed respectively ontheir, extended spindles 8 and 10 one pulley being on i oneside otthehead'struc-r,

7 tlirougha gear couple 17 and the spindle 10 dr-ives its. companion roll .91

through asimilar-gear coup'le,.18;

The cross lbar 13 of the upper front roll 7 is provided with a link- 19 hung or journalled thereon near the left-handeccentric and the corresponding cross bar 13 of the'l ower front roll 9 is simg" drawingceive the ends of an equalizing lever 21 which is thus located vertically below both cross rods, the longer link 19 being apertured or formedas a yoke surrounding the lower cross bar 13 in order to give it clearance. The two links are thus independently connected each to the two eccentric arms of their respective rolls. The equalizing lever 21 is pivotally connected at its center to the offset upper end of the friction bar 22, the lower end of which bar is guided for vertical movement in the frame upright 2 and controlled by the reciprocation of the hammer as customary in board drop hammers. The design of the friction bar controlling means will be recognized from the The hammer is provided with a. pin 23 arranged to strike thelever a; and thereby raise the friction bar, at some point of the upstroke which has been selected as the'npper limit of the hammer movement. Raising the friction bar acts through the equalizing lever 21 and the two pressure links 19 and 20 torock the eccentric arms of both front rolls in the direction to with-r draw those rolls from the board, thus stopping the lifting action on the board and allowing the hammer to fall if the board clamps 5 are not then in position to hold it.

The knock-off mechanism represented generally by 25 and of well-known design, is arranged to hold the friction bar in its raised position, until released by the ham mer, at some selected point in the latters descent. This mechanism is" common in the art andneeds no description. 'The falling of the friction bar pulls the eccentric arms downwards, thereby simultaneously advancing both front rolls against the board and lifting it.' This cycle of operation is repeated as rapidly as the hammer can fall'and be lifted and for as long as the clamps are kept out of action by depression of the foot treadle 6.

It will be apparent that the pressure by which the lifting rolls are pressednpon the board is determined principally by the 7 weight of the friction bar, which is ample for the purpose, and that, thisforce is divided equally by the equalizer 21, between the two links 19 and 20 and hence between the two pairs of rolls so that each pair thus has an equal pressure on the board notwithstanding local or temporary variations in the thickness of the latter, and thereby the friction grip, which each roll has on the board is also substantially equal, and such variation or inaccuracy of adjustment. as may have occurred in the setting of one. or both of the rear rolls 8 and 10 thus becomes automatically and accurately accommodated or compensated and each roll may thus have an adequate lifting effect without exceedingthe maximum pressure which can safely be applied to the board.

The friction bar is so formed, as by means of the shoulders 26 or otherwise, that only a limited amount of angular movement is permitted between itself and the equalizer lever 21; this is enough to produce the equalization in the pressure distribution as above described, but in the-event that eitherroll should stick or tend to lag in withdrawing from the board on the upstroke of the friction bar, the effect of such limited angular movement is to force both rolls to withdraw practically at the same time. Preferably some lost motion or looseness of fit is provided between the friction bar and the pressure links; this accommodates the change of angle between the friction bar and the eccentric arms, incident to the movement of the latter and also allows the friction bar to acquire some momentum prior to its posi-- tive engagement with the links, and thus, so to speak, knocks them open. motion in the present .case is provided by making the equalizer lever 21 as a vertical flat member and the holes in the ends of the two pressures links of corresponding shape but of slightly larger dimensions as indi- The lost cated in Fig. 4, but it will be apparent that the eccentric armof the upper roll :7 by an inclined link 28 and at' its other end to the eccentric arm of the lower roll'9 by a similar link 29, the center of the equalizing lever beingpivotally connected as before to the upper end of the friction bar 22, the axis of the pivot being in this case parallel with the roll axes.

As shown in Fig. 7, the links 28 and 29' are each divided'into pairs, one being adjacent, each eccentric arm'12, and on each side of the equalizer link which is at the middle of the two cross-bars. .In this case also, the head "of. the friction bar is provided with extended shoulders 26 to confine the equalizer to a limited angular movement and thereby constrain a substantially simultaneous withdrawal of both rollsfrom the board as above described.

In Figure 8 the eccentric arms12 of: the rolls 7 and 9'are respectively connected by the links 30 and 31- to an equalizing lever 32 in the form of a gear or pinion journalled on the friction bar,the lower ends'of said links being formed with rack teeth engaging oppositesides of the pinion and being embraced and held up to the pinion i by means of a loop or strapS l. 'It will be l thereby equally pressing the lifting-rolls upon the board. On the ascent of the friction bar the pressure on both rolls is simultaneously relieved and in the event that one of them should lag or stick a supplementary link is provided for producing a positive withdrawal of both. This link is hung from the upper cross bar 13 and engages the other by means of an oblong slot which is of sufiicient length not-to interfere with pressure equalization and yet short enough to compel movement in unison of both arms 'l2'immediately following pressure release as the friction bar ascends, that is to say, as soon as the excess motion permitted by the oblong slot has been taken up, both eccentric arms move together; in the downward movement of the. arms the slot is long enough so that the armsare inf pressure, it will be apparent that other" means may be equally used for this purpose and that there is no limitation to such bar or to any of the details above described except as specifically pointed out'in thefollowing claims. p

I claim: 1 I V 1. In a board drop hammer, the combina-' tion of two pairs of lifting rolls, one roll of each pair being journalled in a movably mounted carrier having an arm. whereby it may be pressed upon the board, a pressureexerting member controlled by the reciprocation of the hammer, and an equalizing lever forming a connection between said memberand the arms of both'carriers and adapted to impart an equal board gripping each pair being movably mounted, a pressure-exerting member controlled by the hammer and-provided with an equalizing lever whereby it acts in one direction toimpartf equalized board-gripping pressure to each roll, and means for limiting the 'an-,

gular movement of said lever whereby the.

action of said member in the opposite direction produces positive withdrawal of both. said lifting'rolls from the board.

3. In a board drop hammer, thecombination of two pairs of lifting rolls, one roll of each pair being'movably mounted whereby it maybe pressed upon the board, a pressure-exerting member controlled by the reciprocation of the hammer, andan equalizing lever disposed parallel to said rolls and connecting said member with both of them and adapted to impart an equal board-gripping pressure to each roll 7 4. In a board drop hammer, the combination of two pairs of lifting rolls, one of the rolls of each pair being movably mounted wherebyit may be pressed upon the board,

a friction bar controlled by the reciprocation of the-hammer and connected to said rolls 'by ,means imparting substantially equal pressure to each, and lost motion means in the pressure-imparting connections.

In a board drop hammer, the combina- I tion of two pairs of lifting-rolls, one of the 1 rolls of each pair being carried in eccentric sleeves, arms on said sleeves, a pressureexerting member connected to-said arms through means adapted to equalize the pres,

sure of each said roll uponthe board and a connections. 7 I v 6. In a board drop hammer, the combinalost motion means in the pressure-imparting tion of two pairs of'lifting rolls, one roll of each 'pairbeing'movably mounted, a pres.- sure-exerting member "controlled by the hammer and provided with an equalizing lever whereby it imparts equalized boardgripping pressure upon each roll, and

means for-simultaneously adjusting the positions ofthe two other rolls with reference to the board.

specification. 7

In testimonywhereof, I have signed this 

